In polymerization type reactions, deposit or buildup of polymer occurs on the inner surface of the reactor which not only interferes with heat transfer, but decreases productivity and adversely affects polymer quality. This problem is particularly troublesome in the commercial production of polymers and copolymers of vinyl and vinylidene halides when polymerized alone or with other vinylidene monomers having a terminal CH.sub.2 .dbd.C&lt; group, or with polymerizable monoolefinic monomers. For example, in the commercial production of vinyl chloride polymers, the same are usually produced in the form of discrete particles by polymerizing in aqueous suspension systems. When employing such systems the vinyl chloride, and other comonomers when used, are maintained in the form of small discrete droplets by the use of suspending agents and agitation. When the reaction is complete, the resultant polymer is washed and dried. The reaction is usually conducted under pressure in metal reactors or glass-lined reactors equipped with baffles and high speed agitators. However, these polymerization systems are, in many cases, unstable. As a consequence, polymer buildup forms on the interior surfaces of the polymerization reactor, including the surfaces of the baffles and agitators. Obviously this polymeric buildup must be removed due to the deleterious effect it causes.
Various methods have heretofore been proposed for removing the polymer buildup on polymerization reactor surfaces, such as solvent cleaning, the use of various hydraulic and mechanical reactor cleaners, and the like. Also, various methods have been proposed to reduce the amount of formation and the nature of polymer buildup on said surfaces, such as the application to said surfaces of various coatings prior to polymerization. In this regard, see, for example, U.S. Pat. Nos. 3,669,946; 4,024,301; 4,024,330; and 4,081,248. These various methods and coatings have done a more than acceptable job. However, the art continues to strive to find the ultimate in the prevention of polymer buildup, particularly from an economic and environmental point of view.
Further, work continues to find more dilute coating solutions not only to reduce costs, considering the size of commercial reactors, but also to reduce the color of the coating solutions, since most all of the known and useful coating solutions are colored. These coating solutions are applied to reactor surfaces in various ways such as, for example by brushing or painting, flooding the reactor, spraying on, and the like. However, efforts continue to find the ultimate means of applying a coating to the reactor surfaces, not only from simplicity of operation and from an economic point of view on a commercial scale, but also a process of application in which the discoloration problem is substantially eliminated or substantially reduced.